Exhaust emissions from diesel engines are known to pose significant health risks and to harmfully impact the environment. Such emissions include solid particulates of carbon and metals as well as hydrocarbons, sulfates and aqueous species which are adsorbed onto the solid particulates. Among the adsorbed species are polynuclear aromatic hydrocarbons (also called PAHs). PAHs are known to cause carcinogenic, mutagenic and teratogenic activity in humans and other mammals.
Considerable effort has been undertaken to reduce the emissions of PAHs from diesel engines. At present, engine exhaust after-treatment devices, such as catalytic converters and particulate traps, have been used to mitigate the release of such toxins. Alternative methods have been sought which will reduce further the release of such toxins from diesel engines.